perf(ivy): improve NaN checks in change detection (#32212)

This commit drops our custom, change-detection specific, equality comparison util
in favour of the standard Object.is which has desired semantics.

There are multiple advantages of this approach:
- less code to maintain on our end;
- avoid NaN checks if both values are equal;
- re-write NaN checks so we don't trigger V8 deoptimizations.

PR Close #32212
This commit is contained in:
Pawel Kozlowski 2019-08-20 11:06:59 +02:00 committed by Andrew Kushnir
parent 53f33c1cec
commit 53bfa7c6d6
5 changed files with 5 additions and 91 deletions

View File

@ -12,8 +12,6 @@ import {throwErrorIfNoChangesMode} from './errors';
import {LView} from './interfaces/view';
import {getCheckNoChangesMode} from './state';
import {NO_CHANGE} from './tokens';
import {isDifferent} from './util/misc_utils';
// TODO(misko): consider inlining
@ -36,9 +34,11 @@ export function bindingUpdated(lView: LView, bindingIndex: number, value: any):
ngDevMode && assertNotSame(value, NO_CHANGE, 'Incoming value should never be NO_CHANGE.');
ngDevMode &&
assertLessThan(bindingIndex, lView.length, `Slot should have been initialized to NO_CHANGE`);
const oldValue = lView[bindingIndex];
if (isDifferent(oldValue, value)) {
if (Object.is(oldValue, value)) {
return false;
} else {
if (ngDevMode && getCheckNoChangesMode()) {
// View engine didn't report undefined values as changed on the first checkNoChanges pass
// (before the change detection was run).
@ -50,8 +50,6 @@ export function bindingUpdated(lView: LView, bindingIndex: number, value: any):
lView[bindingIndex] = value;
return true;
}
return false;
}
/** Updates 2 bindings if changed, then returns whether either was updated. */

View File

@ -6,7 +6,6 @@
* found in the LICENSE file at https://angular.io/license
*/
import {TNode, TNodeFlags} from '../interfaces/node';
import {isDifferent} from '../util/misc_utils';
import {StylingMapArray, StylingMapArrayIndex, TStylingConfigFlags, TStylingContext, TStylingContextIndex, TStylingContextPropConfigFlags} from './interfaces';
@ -160,7 +159,7 @@ export function hasValueChanged(
if (compareValueB instanceof String) {
compareValueB = compareValueB.toString();
}
return isDifferent(compareValueA, compareValueB);
return !Object.is(compareValueA, compareValueB);
}
/**

View File

@ -8,18 +8,6 @@
import {global} from '../../util/global';
import {RElement} from '../interfaces/renderer';
import {NO_CHANGE} from '../tokens';
/**
* Returns whether the values are different from a change detection stand point.
*
* Constraints are relaxed in checkNoChanges mode. See `devModeEqual` for details.
*/
export function isDifferent(a: any, b: any): boolean {
// NaN is the only value that is not equal to itself so the first
// test checks if both a and b are not NaN
return !(a !== a && b !== b) && a !== b;
}
/**
* Used for stringify render output in Ivy.

View File

@ -1010,9 +1010,6 @@
{
"name": "isDevMode"
},
{
"name": "isDifferent"
},
{
"name": "isFactory"
},

View File

@ -1,68 +0,0 @@
/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {devModeEqual} from '@angular/core/src/change_detection/change_detection_util';
import {isDifferent} from '../../src/render3/util/misc_utils';
describe('util', () => {
describe('isDifferent', () => {
describe('checkNoChangeMode = false', () => {
it('should mark non-equal arguments as different', () => {
expect(isDifferent({}, {})).toBeTruthy();
expect(isDifferent('foo', 'bar')).toBeTruthy();
expect(isDifferent(0, 1)).toBeTruthy();
});
it('should not mark equal arguments as different', () => {
const obj = {};
expect(isDifferent(obj, obj)).toBeFalsy();
expect(isDifferent('foo', 'foo')).toBeFalsy();
expect(isDifferent(1, 1)).toBeFalsy();
});
it('should not mark NaN as different', () => { expect(isDifferent(NaN, NaN)).toBeFalsy(); });
it('should mark NaN with other values as different', () => {
expect(isDifferent(NaN, 'foo')).toBeTruthy();
expect(isDifferent(5, NaN)).toBeTruthy();
});
});
describe('checkNoChangeMode = true', () => {
// Assert relaxed constraint in checkNoChangeMode
it('should not mark non-equal arrays, object and function as different', () => {
expect(!devModeEqual([], [])).toBeFalsy();
expect(!devModeEqual(() => 0, () => 0)).toBeFalsy();
expect(!devModeEqual({}, {})).toBeFalsy();
});
it('should mark non-equal arguments as different', () => {
expect(!devModeEqual('foo', 'bar')).toBeTruthy();
expect(!devModeEqual(0, 1)).toBeTruthy();
});
it('should not mark equal arguments as different', () => {
const obj = {};
expect(isDifferent(obj, obj)).toBeFalsy();
expect(isDifferent('foo', 'foo')).toBeFalsy();
expect(isDifferent(1, 1)).toBeFalsy();
});
it('should not mark NaN as different', () => { expect(isDifferent(NaN, NaN)).toBeFalsy(); });
it('should mark NaN with other values as different', () => {
expect(isDifferent(NaN, 'foo')).toBeTruthy();
expect(isDifferent(5, NaN)).toBeTruthy();
});
});
});
});